Having just reached level 4, I want my battlemind PC that's just taken the feat Hero of the Faith (Divine Power 144)—picking the skill Streetwise—to retrain his level 2 battlemind utility power feather step to the level 2 skill power secrets of the city (Dragon #389 36). Player's Handbook 3 on Gaining and Using a Skill Power, in part, says
You can gain and use only the skill powers associated with your trained skills. Whenever you reach a level that grants you a utility power from your class, you can choose a skill power in place of a class power. The skill power you choose must be of the same level as or lower in level than the class power you would have gained.
You can use retraining… to replace a class power with a skill power and vice versa, as long as the new power is of the same level as or lower in level than the replaced power. (164)
However, the Rules Compendium on Swapping Powers, in part, says
You might be given the option of swapping a class power for a power that is not from your character’s class [e.g. a skill power?]. You cannot make the swap if doing so would eliminate your character’s last class power of a particular type: utility power, at-will attack power, encounter attack power, or daily attack power. For instance, if your wizard has only one wizard utility power, you cannot swap that power for a nonwizard power. (90 and emphases mine)
Now, even though the skill power isn't a battlemind power, I boldly assumed that the specific rules for skill powers overrode the general rules for swapping powers, so my battlemind was in the clear.
My confusion, though, comes from this thread that in 2017 has this question about this situation and received here the answer Yes, you can take the skill power at level 2 then received here the different answer No, you gotta wait until level 6. (To be extra murky, the Rules Compendium doesn't acknowledge the existence of skill powers.)
Was this ever resolved? Is it okay for a level 2 character to take a utility skill power? (Or, in this case, for my level 4 character to retrain into one?) Or must a character wait until level 6 when he gets his second utility power to take his first utility skill power so that the character has one utility power from his class and a second utility skill power?